The hacksaw is a cutting tool for metal or bone. Some have grips that keep the saw steady and make it easy to handle. The blade "Blade (tool)") is fine-toothed and tensioned on a mount.

These saws, designed to primarily cut metal, are categorized by the number of teeth per inch. The standard saw blade has between 14 and 32 teeth per inch. The set of teeth, how they are angled relative to the sides of the blade, determines how well the saw cuts. Metal saws cut many things from thin copper pipes to rusty screws, garden hoses, pipes, plastics, old fences, etc.

32 teeth per inch

A saw blade with 32 teeth per inch provides a finer cut and is good for cutting thin gauge steel or tubing, copper tubing, or heating ducts.

24 teeth per inch

24 teeth per inch saw blades are used for medium pipe and regular wall pipe. According to the Aviation, Integrated Publishing website, 24-tooth blades are also good for cutting angle iron, thick pipe, tin, and copper. Nuts, stubborn screws and corrugated iron are cut with this blade.

18 teeth per inch

18 teeth per inch saw blades are used for hard iron pipes and large pieces of steel. If you are cutting through an old pipe or chain link, use this blade.

14 teeth per inch

Saws with 14 teeth per inch work quite well with soft metals such as aluminum and tin. This blade cuts electrical cable, aluminum chairs and plastic windows.

12 teeth per inch, bimetal

Bimetal blades have 12 teeth per inch and are used for high speed pipe, plastic, wood or iron. This blade is good for cutting garden hoses, picture frames, and plastic chairs.

There are four different series, or angles, of teeth, according to the Aviation, Integrated Publishing website: